Technical Library | 2015-04-16 16:11:43.0
Solder ball height inspection is essential to the detection of potential connectivity issues in semi-conductor units. Current ball height inspection tools such as laser profiling, fringe projection and confocal microscopy are expensive, require complicated setup and are slow, which makes them difficult to use in a real-time manufacturing setting. Therefore, a reliable, in-line ball height measurement method is needed for inspecting units undergoing assembly. (...) In this paper, an automatic, stereo vision based, in-line ball height inspection method is presented. The proposed method includes an imaging setup together with a computer vision algorithm for reliable, in-line ball height measurement.
Technical Library | 2024-04-29 21:39:52.0
In this paper, we develop and put into practice an Automatic Optical Inspection (AOI) system based on machine vision to check the holes on a printed circuit board (PCB). We incorporate the hardware and software. For the hardware part, we combine a PC, the three-axis positioning system, a lighting device and CCD cameras. For the software part, we utilize image registration, image segmentation, drill numbering, drill contrast, and defect displays to achieve this system. Results indicated that an accuracy of 5µm could be achieved in errors of the PCB holes allowing comparisons to be made. This is significant in inspecting the missing, the multi-hole and the incorrect location of the holes. However, previous work only focusses on one or other feature of the holes. Our research is able to assess multiple features: missing holes, incorrectly located holes and excessive holes. Equally, our results could be displayed as a bar chart and target plot. This has not been achieved before. These displays help users analyze the causes of errors and immediately correct the problems. Additionally, this AOI system is valuable for checking a large number of holes and finding out the defective ones on a PCB. Meanwhile, we apply a 0.1mm image resolution which is better than others used in industry. We set a detecting standard based on 2mm diameter of circles to diagnose the quality of the holes within 10 seconds.
Technical Library | 2017-04-27 17:10:16.0
Using modern laser systems for the depanelization of circuit boards can create some challenges for the production engineer when it is compared to traditional mechanical singulation methods. Understanding the effects of the laser energy to the substrate material properly is essential in order to take advantage of the technology without creating unintended side effects. This paper presents an in-depth analysis of the various laser system operating parameters that were performed to determine the resulting substrate material temperature changes. A theoretical model was developed and compared to actual measurements. The investigation includes how the temperature increase resulting from laser energy during depaneling affects the properties of the PCB substrate, which varies from no measurable change to a lowering of the surface resistance of the cut wall depending on the cutting parameters.
Technical Library | 2020-03-26 14:55:29.0
This paper introduces line confocal technology that was recently developed to characterize 3D features of various surface and material types at sub-micron resolution. It enables automatic microtopographic 3D imaging of challenging objects that are difficult or impossible to scan with traditional methods, such as machine vision or laser triangulation.Examples of well-suited applications for line confocal technology include glossy, mirror-like, transparent and multi-layered surfaces made of metals (connector pins, conductor traces, solder bumps etc.), polymers (adhesives, enclosures, coatings, etc.), ceramics (components, substrates, etc.) and glass (display panels, etc.). Line confocal sensors operate at high speed and can be used to scan fast-moving surfaces in real-time as well as stationary product samples in the laboratory. The operational principle of the line confocal method and its strengths and limitations are discussed.Three metrology applications for the technology in electronics product manufacturing are examined: 1. 3D imaging of etched PCBs for micro-etched copper surface roughness and cross-sectional profile and width of etched traces/pads. 2. Thickness, width and surface roughness measurement of conductive ink features and substrates in printed electronics applications. 3. 3D imaging of adhesive dots and lines for shape, dimensions and volume in PCB and product assembly applications.
Technical Library | 2013-01-11 16:51:33.0
There have been claims in the industry that laser-cut electroformed nickel foil blanks provide stencil print performance comparable to electroformed stencils. A study was established to measure the quantitative differences in performance between the two during an independent lab study.
Technical Library | 2019-09-11 23:33:04.0
There are numerous techniques to singulate printed circuit boards after assembly including break-out, routing, wheel cutting and now laser cutting. Lasers have several desirable advantages such as very narrow kerf widths as well as virtually no dust, no mechanical stress, visual pattern recognition and fast set-up changes. The very narrow kerf width resulting from laser ablation and the very tight tolerance of the cutting path placement allows for more usable space on the panel. However, the energy used in the laser cutting process can also create unwanted products on the cut walls as a result of the direct laser ablation. The question raised often is: What are these products, and how far can the creation of such products be mitigated through variation of the laser cutting process, laser parameters and material handling? This paper discusses the type and quantity of the products found on sidewalls of laser depaneled circuit boards and it quantifies the results through measurements of breakdown voltage, as well as electrical impedance. Further this paper discusses mitigation strategies to prevent or limit the amount of change in surface quality as a result of the laser cutting process. Depending on the final application of the circuit board it may prompt a need for proper specification of the expected results in terms of cut surface quality. This in turn will impact the placement of runs and components during layout. It will assist designers and engineers in defining these parameters sufficiently in order to have a predictable quality of the circuit boards after depaneling.
Technical Library | 2012-10-25 16:34:02.0
First published in the 2012 IPC APEX EXPO technical conference proceedings. This paper will examine stencil technologies (including Laser and Electroform), Aperture Wall coatings (including Nickel-Teflon coatings and Nano-coatings), and how these parameters influence paste transfer for miniature devices with Area Ratios less than the standard recommended lower limit of .5. A matrix of print tests will be utilized to compare paste transfer and measure the effectiveness of the different stencil configurations. Area Ratios ranging from .32 to .68 will be investigated.
Technical Library | 2019-05-23 21:56:56.0
Automatic on-line shoe sole spraying system: automatic shoe sole spraying system, simple and convenient operation, using 3D vision positioning system. Automatic recognition and automatic generation of spraying trajectory. Robot non-contact spraying gun is used to complete the process of shoe sole spraying with maturity, stability, high speed and high precision along the predetermined trajectory. The automatic generation of spraying trajectory is the realization of shoe sole spraying technology. Shoe sole spraying characteristics: 1.Positioning System: 3D Visual Positioning 2.Components: Intelligent Robot, Laser Scanner, Industrial Computer, Gum Spraying System, Conveyor Belt, Electrical Control System, etc. 3.Spraying time: slightly different according to shoe size and spraying time Fully automatic sole spraying advantages: 1. Simple application: suitable for soles of different specifications, models and sizes 2. Faster speed: 6-8 seconds to complete sole scanning and spraying, superior to similar products at home and abroad. 3. Quality stability: gum spraying trajectory is scheduled, gum dosage is fixed, gum spraying quality is greatly improved. 4. High cost performance: the same performance, the price is only 1/3 of the same type of equipment of European brand. 5. Reduce wear and tear: glue is fully utilized and not wasted, reducing human contact with glue. Intelligent operation advantage manual only need general operation can be automated workshop, mechanical arm automatic spraying glue, accurate spraying, reduce glue waste. Environmental protection effect of long-term close contact with glue seriously affects human health and mechanical work, glue does not directly contact, do not harm the human body. Fully automatic spraying, shoe sole adhesion process for automatic spraying machine, will not cause great challenges! With the deepening of personalized shoemaking, higher requirements have been put forward for the spraying technology in shoemaking process. The method of creating spraying trajectory must be adapted to shoes of different sizes and styles. The automatic generation of spraying trajectory is one of the key technologies to realize the automation of shoe sole spraying process. The method of off-line programming and real-time generation of spraying trajectory for robots based on the three-dimensional CAD model of sole and the data of sole. A new method of generating spray trajectory by scanning the sole of shoe upper with linear structured light sensor is presented. The feasibility of the method is verified by industrial robots. Aiming at the need of generating shoe sole spray rubber trajectory based on line structured light, the format standard of IGES file of three-dimensional model of shoe sole was tested. The shoe sole contour line and the shoe sole surface were extracted, and then the offset curve of the shoe sole contour line on the shoe sole surface was calculated to obtain the spray rubber trajectory. Three-dimensional profilometer is to use structured light to obtain sole information, effectively improve the automatic shoemaking spraying process, which will help to improve the efficiency of shoemaking, improve the quality of footwear products, and promote the development of personalized shoemaking.
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